Ring Type Joints

Metallic ring joint gaskets are heavy duty, high-pressure gaskets largely used in offshore and onshore petrochemical applications. They are precision-engineered components designed to be used in conjunction with precision-machined flanges. All our Ring Joints are manufactured according to ASME B16.20 and API 6A.

The gasket material is selected on a number of grounds primarily; chemical compatibility with the media and the hardness of the flange. The gasket material ideally needs to be roughly 30 Brinell less than the flange material to ensure sufficient deformation of the gasket without damaging the flange facing.

Worn, pitted or corroded flange sealing surfaces can impede the sealing ability of RTJ gaskets. In such instances, a serrated octagonal RTJ gasket, covered with flexible graphite or a Maxiflex CR-RJ, can provide a temporary or emergency solution until the flange can be repaired or replaced.

A number of ring joint styles are available designed for specific flange types, these are:

Type R Oval & Octagonal

- NB1/2" to 24" Class Rating 150 to 2500 ASME B16.20

- NB26" to 36" Class 300 to 900 ASME B16.20 Series A

- NB1/2" to 20" Class API 6A

Type RX

- NB1 1/2" to 24" Class Rating 720 to 5000 ASME B16.20

- NB26" to 36" Class Rating 300 to 900 ASME B16.20 Series A

- NB1 1/2" to 20" Class Rating API 6A

Type BX

- NB1 11/16" to 21 1/4" Class Rating 5000 to 20000 ASME B16.20

Common Materials

Material

Brinell Hardness

Temperature Limitations

Identification

Soft Iron

90

-60 to +400 °C

D

Low carbon steel

120

-40 to +500°C

S

4%-6% Cr ½% Mo:F5

130

-125 to +500°C

F5

Stainless steel 304/304L

160

-250 to +650°C

S304 or 304L

Stainless steel 316/316L

160

-196 to +800°C

S316 or 316L

Stainless steel 321

160

-250 to +870°C

S321

Stainless steel 347

160

-250 to +870°C

S347

Stainless steel 410

170

-20 to +500°C

S410

Inconel 625

-

1000°C

625

Incoloy 825

-

1000°C

825

Hastelloy C-276

-

1000°C

C-276

Duplex

-

800°C

S31803

Titanium

-

540°C

TI

The sealing surfaces on the ring joint grooves must be smoothly finished to 63 Microinches and be free of objectionable ridges, tool or chatter marks.